Flexible Sensors for Sport-Specific Applications: A Review of Performance Assessment, Motion Recognition, and Injury Risk Monitoring

Flexible sensors have shown significant potential for sport-specific monitoring owing to their lightweight, soft, stretchable, conformable, and wearable characteristics. This review summarizes the applications of flexible sensors in typical sports, including basketball, volleyball, table tennis, football, badminton, tennis, swimming, and running, with a particular focus on their roles in performance assessment, sport-specific motion recognition, and injury risk monitoring. Existing studies indicate that flexible sensors can continuously, real-time, and precisely collect information on joint motion, plantar pressure, grip pressure, impact force, body posture, physiological status, and fatigue-related changes. These data provide valuable support for technical movement evaluation, training load regulation, motion classification, and injury risk warning. Moreover, by integrating machine learning, deep learning, wireless transmission, and self-powered technologies, flexible sensors are expected to promote the development of sport-specific monitoring toward intelligent and individualized applications. However, their practical use in real sports scenarios still faces several challenges, including insufficient sport-specific adaptability, limited signal stability, inadequate long-term wearing reliability, difficulties in multimodal integration, and a lack of data standardization. Future research should focus on material optimization, system integration, artificial intelligence-based modeling, and validation in real-world sports environments, thereby facilitating the practical application of flexible sensors in intelligent sports training, injury prevention, and sports health management.